Exposure apparatus and device manufacturing method

ABSTRACT

An exposure apparatus which prevents the damage due to the liquid having flowed out from spreading and enables satisfactory performances of the exposure processes and the measurement processes is provided. An exposure apparatus (EX) includes a movable table (PT), a base member ( 41 ) having an upper surface ( 41 A) that guides the movement of the table (PT), and a detecting device ( 60 ) that detects whether there is a liquid on the upper surface ( 41 A) of the base member ( 41 ).

TECHNICAL FIELD

The present invention relates to an exposure apparatus that exposes asubstrate via a liquid and to a device manufacturing method.

The present application claims priority to Japanese Patent ApplicationNo. 2004-205009, filed on Jul. 12, 2004, and its content is incorporatedherein by reference.

BACKGROUND ART

Semiconductor devices and liquid crystal display devices aremanufactured through the so-called photolithography technique, by whicha pattern formed on a mask is transferred onto a photosensitivesubstrate. The exposure apparatus used in the photolithography processhas a mask stage that supports a mask and a substrate stage thatsupports a substrate, and while successively moving the mask stage andthe substrate stage, transfers the mask pattern, via a projectionoptical system, onto the substrate. In recent years, to address theincreasingly high integration of device patterns, increasingly highresolution of the projection optical system has been desired. Theshorter the exposure wavelength used is, and, also, the larger thenumerical aperture of the projection optical system is, the higher theresolution of the projection optical system becomes. For this reason,the exposure wavelength used for the exposure apparatus is becomingshorter and shorter year by year, and the numerical aperture of theprojection optical system is also becoming larger and larger. In thiscontext, the presently dominant exposure wavelength is 248 nm from a KrFexcimer laser, but a still shorter wavelength of 193 nm from an ArFexcimer laser is now gradually being put to practical use.

In addition, when performing exposure, the depth of focus (DOF) is animportant factor along with the resolution. The resolution R and thedepth of focus δ are respectively expressed by the following formulas:R=k ₁ ·λ/NA,  (1)δ=±k ₂ ·λ/NA ²,  (2)where λ is the exposure wavelength, NA is the numerical aperture of theprojection optical system, and k₁ and k₂ are process coefficients. Itcan be seen from formulas (1) and (2) that if, to enhance the resolutionR, the wavelength λ is made shorter and the numerical aperture is madelarger, then the depth of focus δ becomes narrower.

When the depth of focus δ becomes too narrow, it becomes difficult tomake the substrate surface coincide with the image plane of theprojection optical system, and thus there occurs the possibility thatthe focus margin during the exposure operation will be insufficient. Toaddress this problem, the liquid immersion method, which is disclosedin, e.g., Patent Document 1 mentioned below, has been proposed as amethod to make the exposure wavelength shorter in effect and to make thedepth of focus broader. This liquid immersion method is designed to, byfilling the space between the under surface of the projection opticalsystem and the substrate surface with a liquid, e.g., water or organicsolvent to form a liquid immersion region and thus by taking advantageof the fact that the wavelength of the exposure light in the liquidbecomes 1/n times (n is the refractive index of the liquid and isgenerally about 1.2 to 1.6) of that in the air, improve the resolutionand, at the same time, enlarge the depth of focus by approximately ntimes. Patent Document 1: International Publication WO 99/49504

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

By the way, when the liquid of the liquid immersion region or the liquidfor exposure flows out, and the condition is left as it is, the ambience(humidity etc.) in which the exposure apparatus is placed changes, andthus there occur disadvantages, e.g., a disadvantage that themeasurement accuracies deteriorate with the ambience change of theoptical paths of the interferometers for measuring the position of thestages occurring. Also, there is the possibility that there occurdisadvantages due to the liquid having flowed out, e.g., a disadvantagethat the surrounding devices etc. break down, are subject to an electricleakage, or rust, and thus the exposure accuracy and the measurementaccuracies may deteriorate. Further, when the liquid having flowed outexpands, it may for example adversely affect, e.g., various devicesconstituting the exposure apparatus, spreading the damage.

The present invention has been made in consideration of such situations,and its objective is to provide an exposure apparatus which prevents thedamage due to the liquid having flowed out from spreading and by whichthe exposure processes and the measurement processes can be performedsatisfactorily and to provide a device manufacturing method.

MEANS FOR SOLVING PROBLEM

To resolve the above-described problems, the present invention adoptsthe following configurations corresponding to FIGS. 1 to 24 asillustrated in embodiments. It is to be noted that the parenthesizedletter or numeral attached to each constituent element merelyexemplifies such element, with which it is not intended to limit therespective elements.

The exposure apparatus (EX) of the present invention, that exposes asubstrate (P) via a liquid (LQ), comprising a movable table (PT, PT1,PT2), a base member (41) having an upper surface (41A) that guides themovement of the table (PT, PT1, PT2), and a detecting device (60) thatdetects whether there is a liquid (LQ) on the upper surface (41A) of thebase member (41).

According to the present invention, there is provided the detectingdevice that detects whether there is a liquid on the upper surface ofthe base member that guides the movement of the table, and thus when thedetecting device detects a liquid, an appropriate step or measurement,e.g., a step to remove the liquid can be promptly taken. Thus, thedamage due to the liquid having flowed out is prevented from spreading,and the exposure processes and the measurement processes can beperformed satisfactorily.

Further, the exposure apparatus (EX) of the present invention, thatexposes a substrate (P) via a liquid (LQ), comprising a detecting device(60) that is capable of detecting a liquid (LQ) and a movable member(44, 50, PT, etc.) that while supporting the detecting device (60), ismovable.

According to the present invention, the detecting device that is capableof detecting a liquid is supported and moved by the movable member,thus, it is possible to detected whether there is a liquid with respectto an area of a relatively large, detectable area. Therefore, the damagedue to the liquid having flowed out is prevented from spreading, and theexposure processes and the measurement processes can be performedsatisfactorily.

The device manufacturing method of the present invention utilizes theabove-described exposure apparatus (EX).

Since, according to the present invention, the exposure processes andthe measurement processes can be performed satisfactorily, deviceshaving a desired performance can be manufactured.

EFFECT OF THE INVENTION

Since, according to the present invention, the damage due to the liquidhaving flowed out is prevented from spreading, the exposure processesand the measurement processes can be performed satisfactorily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an embodiment of an exposureapparatus of the present invention.

FIG. 2 is a schematic diagram showing a substrate table.

FIG. 3 is a plan view of the substrate table as viewed from above.

FIG. 4 is a diagram for illustrating the condition where a detectingdevice is detecting a liquid.

FIG. 5 is a diagram showing the positional relationship between adetecting light and the surface of a base member.

FIG. 6 is a drawing for illustrating an example of the irradiatingposition of the detecting light.

FIG. 7 is a drawing for illustrating the condition where the substratetable moves between an exposure position and an unload position.

FIG. 8 is a drawing showing another condition where the detecting deviceis detecting a liquid.

FIG. 9 is a drawing showing a modified example of the setting positionof the detecting device.

FIG. 10 is a drawing showing a modified example of the setting positionof the detecting device.

FIG. 11 is a drawing showing a modified example of the setting positionof the detecting device.

FIG. 12 is a drawing showing another embodiment of the detecting device.

FIG. 13 is a drawing showing another embodiment of the detecting device.

FIG. 14 is a drawing showing another embodiment of the detecting device.

FIG. 15 is a drawing showing another embodiment of the detecting device.

FIG. 16 is a drawing showing another embodiment of the detecting device.

FIG. 17 is a drawing for illustrating a liquid recovery mechanism thatrecovers a liquid on the base member.

FIG. 18 is a drawing showing the positional relationship between aliquid recovery port provided to an air bearing and the detectingdevice.

FIG. 19 is a drawing showing an example of an exposure apparatuscomprising a first table and a second table.

FIG. 20 is a drawing showing another embodiment of the detecting device.

FIG. 21 is a cross-sectional view along the line A-A of FIG. 20.

FIG. 22 is a perspective view showing another embodiment of the liquidrecovery mechanism.

FIG. 23 is a drawing showing another embodiment of the detecting device

FIG. 24 is a flowchart showing an example of a semiconductor-devicemanufacturing process.

DESCRIPTION OF THE REFERENCE SYMBOLS

1 . . . liquid immersion mechanism; 2 . . . optical element; 10 . . .liquid supply mechanism; 20 . . . liquid recovery mechanism; 26 . . .liquid recovery port; 29 . . . second liquid recovery mechanism; 41 . .. base member; 41A . . . upper surface; 41B . . . side surface; 42 . . .air bearing; 42A . . . air suction port; 42B . . . blowout port; 42E . .. peripheral region; 42S . . . bearing surface; 42T . . . center region;46 . . . laser interferometer; 50 . . . guided member; 50A . . . firstguiding member; 50B . . . second guiding member; 60 . . . detectingdevice; 61 . . . floodlighting portion; 62 . . . light receivingportion; 65A-65E . . . detecting device; 70 . . . nozzle member; CONT .. . controller; EX . . . exposure apparatus; FD . . . floor face; La . .. detecting light; LQ . . . liquid; P . . . substrate; PST . . .substrate stage; PSTD . . . substrate stage driving mechanism; PT . . .substrate table; PT1 . . . measurement table PT2. . . measurement table;PTA . . . substrate table undersurface; PTE . . . substrate table edgeportion.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, embodiments of the present invention will be describedreferring to the drawings. FIG. 1 is a schematic diagram showing anembodiment of an exposure apparatus of the present invention.

In FIG. 1, exposure apparatus EX comprises mask table MT that is movablewhile holding mask M, with substrate table PT that is movable whileholding substrate P, with illumination optical system IL thatilluminates mask M supported by mask table MT with exposure light EL,with projection optical system PL that projects a pattern image of maskM illuminated with exposure light EL onto substrate P supported bysubstrate table PT, and with controller CONT that controls the overalloperation of exposure apparatus EX. To controller CONT is connectedalarm device K that raises an alarm when a problem occurs with respectto the exposure process.

Further, exposure apparatus EX comprises main column 3 that supportsprojection optical system PL etc. Main column 3 is set on surface plate4 which is placed horizontally on floor face FD. Main column 3 comprisesupper side stage portion 3A and lower side stage portion 3B thatprotrude toward the inside thereof.

Exposure apparatus EX of this embodiment is a liquid immersion exposureapparatus to which a liquid immersion method is applied, with theexposure wavelength being shortened in effect, to improve the resolutionand, at the same time, to widen the depth of focus. Exposure apparatusEX comprises liquid immersion mechanism 1 that is capable of formingliquid immersion region AR2 of liquid LQ on substrate P. Liquidimmersion mechanism 1 comprises liquid supply mechanism 10 that suppliesliquid LQ onto substrate P and with liquid recovery mechanism 20 thatrecovers liquid LQ on substrate P. Exposure apparatus EX adopts a localliquid immersion system in which, at least while transferring thepattern image of mask M onto substrate P, liquid immersion region AR2 islocally formed by liquid LQ having been supplied from liquid supplymechanism 10 on a substrate P's portion that includes projection areaAR1 of projection optical system PL. Liquid immersion region AR2 that islarger than projection area AR1 and is smaller than substrate P. Morespecifically, exposure apparatus EX, by filling with liquid LQ the spacebetween optical element 2 located on the projection optical system PL'simage plane side end and the surface of substrate P, forms liquidimmersion region AR2 and, by projecting the pattern image of mask M ontosubstrate P via this liquid LQ between projection optical system PL andsubstrate P, exposes substrate P.

Further, in the vicinity of the image plane of projection optical systemPL, specifically, in the vicinity of optical element 2, which is locatedon the projection optical system PL's image plane side end, nozzlemember 70 which constitutes a portion of liquid immersion mechanism 1 isdisposed. Nozzle member 70 is a ring-shaped member that is disposed soas to surround, over or above substrate P (substrate table PT), the endportion of projection optical system PL.

Further, as will be later described in detail, exposure apparatus EXcomprises base member 41 having upper surface 41A that guides themovement of substrate table PT and comprises detecting device 60 thatdetects whether there is liquid LQ on upper surface 41A of base member41.

The embodiment will be described by assuming, as an example, a casewhere as exposure apparatus EX, a scan type exposure apparatus (theso-called scanning stepper) in which while synchronously moving mask Mand substrate P in the directions, along the scanning directiondifferent from each other (opposite directions), the pattern formed onmask M is exposed onto substrate P is used. In the followingdescription, it is assumed that the direction that coincides withoptical axis AX of projection optical system PL is referred to as theZ-axis direction, that the synchronous movement direction (scanningdirection), in a plane perpendicular to the Z-axis direction, of mask Mand substrate P is referred to as the X-axis direction, and that thedirection perpendicular to the Z-axis direction and to the X-axisdirection (non-scanning direction) is referred to as the Y-axisdirection. Further, it is assumed that the direction around the X-axis,the direction around the Y-axis, and the direction around the Z-axis arerespectively referred to as the OX-direction, the θY-direction, and theθZ-direction. It should be noted that a “substrate” referred to hereinincludes a semiconductor wafer over which photoresist which is aphotosensitive material is applied, and a “mask” includes a reticle onwhich a device pattern to be reduction-projected onto the substrate isformed.

Illumination optical system IL is supported by supporting column 5 thatis fixed on the upper portion of main column 3. Illumination opticalsystem IL is for illuminating mask M supported by mask table MT withexposure light EL and comprises an exposure light source, an opticalintegrator for uniformizing the illuminance of the light flux emittedfrom the exposure light source, a condenser lens for condensing exposurelight EL from the optical integrator, a relay lens system, a field stopfor setting an illumination area formed by exposure light EL on mask M,etc. A specified illumination area on mask M is illuminated, byillumination optical system IL, with exposure light EL having a uniformilluminance distribution. As exposure light EL emitted from illuminationoptical system IL, for example, a bright line (g-line, h-line, i-line)emitted from a mercury lamp, a deep ultraviolet light (DUV light) suchas a KrF excimer laser light (wavelength of 248 nm), or a vacuumultraviolet light (VUV light) such as an ArF excimer laser light(wavelength of 193 nm) or an F₂ excimer laser light (wavelength of 157nm) may be used. In the embodiment, an ArF excimer laser light is used.

In the embodiment, purified water is used as liquid LQ. Purified watercan transmit not only an ArF excimer laser light but also, for example,a bright line (g-line, h-line, or i-line) emitted from a mercury lampand a deep ultraviolet light (DUV light) such as a KrF excimer laserlight (wavelength of 248 nm).

Mask table MT is configured to be movable, while holding mask M. Atupper side stage portion 3A of main column 3 is supported base member 31via vibration isolation unit 6. On the undersurface of mask table MT areprovided a plurality of gas bearings (air bearings) 32, which arenon-contact type bearings. Mask table MT is supported by air bearings 32in a non-contact manner relative to upper surface (guide surface) 31A ofbase member 31 and, by a mask table driving mechanism including a linearmotor etc., mask table MT is two-dimensionally movable in a planeperpendicular to optical axis AX of projection optical system PL, i.e.,in the XY-plane, and is finely rotatable in the θZ-direction. At least aportion of mask stage MST, which moves while supporting mask M, isconstituted by the above-described mask table MT, mask table drivingmechanism, etc.

Mask table MT is provided with moving mirror 35. Further, laserinterferometer 36 is provided at a position facing moving mirror 35. Thetwo-dimensional position and the rotation angle in the θZ-direction(including the rotation angles in the θX- and θY-directions in somecases) of mask table MT supporting mask M are measured by laserinterferometer 36 in real time, and the measurement results areoutputted to controller CONT. By driving the mask table drivingmechanism based on the measurement results from laser interferometer 36,controller CONT controls the position of mask M supported by mask tableMT.

Projection optical system PL is for projecting the pattern of mask Monto substrate P at a predetermined projection magnification of P.Projection optical system PL is constituted by a plurality of opticalelements including optical element (lens) 2 disposed in the projectionoptical system's end portion on the side of substrate P, and theseoptical elements are supported by lens barrel PK. Optical element 2,which is located in the projection optical system PL's end portion,protrudes from lens barrel PK. Optical element 2 is configured so as tocome into contact liquid LQ of liquid immersion region AR2. Further,optical element 2's liquid contact surface (undersurface) 2A that comesinto contact liquid LQ of liquid immersion region AR2 isliquid-attractive or lyophilic to liquid LQ.

In the embodiment, projection optical system PL is a reduction system ofwhich projection magnification β is, e.g., ¼, ⅕, or ⅛. It should benoted that projection optical system PL may also be either a unitmagnification system or a magnifying system. Further, projection opticalsystem PL may be either one of a refractive system which does notinclude any reflective optical member, a reflection system which doesnot include any refractive optical element, or a catadioptric systemwhich includes a reflective optical member and a refractive opticalelement. Lens barrel surface plate 8 supporting projection opticalsystem PL's lens barrel PK is supported by lower side stage portion 3Bof main column 3 via vibration isolation unit 7.

Substrate table PT is configured to be movable, while holding substrateP via substrate holder PH. Concave portion 53 is provided on substratetable PT, and substrate holder PH is disposed in concave portion 53.Further, substrate table PT's top face 43 is a flat surface, and topface 43 and the surface of substrate P held by substrate holder PH aresubstantially flush with each other.

On the undersurface of substrate table PT are provided a plurality ofgas bearings (air-bearings) 42, which are non-contact type bearings.Base member 41 is supported on surface plate 4 via vibration isolationunit 9. A air bearings 42 have bearing surfaces 42S that face uppersurface (guide surface) 41A of base member 41. Air bearings 42 compriseblowout ports 42B that are provided in bearing surfaces 42S and blow agas (air) against base member 41's upper surface 41A and air suctionports 42A that are provided in bearing surfaces 42S and suck the gasbetween bearing surfaces 42S and guide surface 41A. Air bearings 42 keepa constant gap between substrate table PT's undersurface PTA (bearingsurfaces 42S) and guide surface 41A through a balance between therepulsive force caused by the gas blowing from blowout ports 42B and thesucking force by air suction ports 42A. Air bearings 42 supportsubstrate table PT relative to upper surface 41A of base member 41 in anon-contact manner. Substrate table PT is guided, in the state of beingsupported by air bearings 42 in a non-contact manner relative to basemember 41's upper surface 41A, over base member 41's upper surface 41Aby substrate stage driving mechanism PSTD including the below-describedlinear motors 47 and 48, X-guide stage 44, and guided members 50, whilesubstrate table PT is two-dimensionally movable in a plane perpendicularto optical axis AX of projection optical system PL, i.e., in theXY-plane, and is finely rotatable in the θZ-direction. Further,substrate holder PH on substrate table PT is provided such that it canbe moved in the Z-axis-, θX-, and θY-directions by a holder drivingmechanism, not shown. Substrate stage PST that moves while supportingsubstrate P is constituted by substrate table PT, substrate stagedriving mechanism PSTD, etc. The holder driving mechanism and substratestage driving mechanism PSTD are controlled by controller CONT.

Further, exposure apparatus EX comprises a focus-leveling detectionsystem, not shown, that detects the position of the surface of substrateP supported by substrate table PT. The focus-leveling detection systemdetects the position information, in the Z-axis-direction, of thesubstrate P's surface and the inclination information, in the θX- andθY-directions, of substrate P. It is to be noted that as theconfiguration of the focus-leveling detection system, such aconfiguration as disclosed in, e.g., Japanese Unexamined PatentPublication Hei 8-37149 may be used. The detection results from thefocus-leveling detection system are outputted to controller CONT. Bydriving the holder driving mechanism based on the detection results fromthe focus-leveling detection system, controller CONT controls the focusposition (Z-position) and inclination angles of the surface of substrateP to adjust the surface of substrate P to the image plane of projectionoptical system PL.

Substrate table PT comprises moving mirror 45. Further, laserinterferometer 46 is positioned at a position facing moving mirror 45.The two-dimensional position and rotation angle of substrate table PTsupporting substrate P are measured by laser interferometer 46 in realtime, and the measurement results are outputted to controller CONT. Bydriving substrate stage driving mechanism PSTD based on the measurementresults from laser interferometer 46, controller CONT performs thepositioning, in the X-axis-direction and Y-axis direction, of substrateP supported by substrate table PT.

Substrate table PT is supported by X-guide stage 44 so as to movable inthe X-axis-direction. Being guided by X-guide stage 44, substrate tablePT can be moved by X-linear motor 47 in the X-axis direction within apredetermined stroke. X-linear motor 47 comprises stator 47A that isprovided to X-guide stage 44 so as to extend in the X-axis-direction andmover 47B that is provided so as to correspond stator 47A and is fixedon substrate table PT. Thus, with mover 47B being driven relative tostator 47A, substrate table PT moves in the X-axis-direction in a stateof being supported in a non-contact manner by X-guide stage 44.

On both ends in the longitudinal direction of X-guide stage 44 areprovided a pair of Y-linear motors 48 that are capable of moving X-guidestage 44, along with substrate table PT, in the X-axis-direction. Eachof Y-linear motors 48 comprises mover 48B that is provided on each ofboth ends in the longitudinal direction of X-guide stage 44 and stator48A that is provided so as to correspond to mover 48B. Thus, with movers48B being driven relative to stators 48A, X-guide stage 44 moves alongwith substrate table PT in the Y-axis-direction. Further, it isconfigured such that with each of the drives of Y-linear motors 48 beingadjusted, X-guide stage 44 and substrate table PT are be rotationallymovable also in the θX-direction.

A guide portion 49 is provided on each of the X-axis-direction sides ofbase member 41. Guide portion 49 is formed in an L shape and guides theY-axis-direction movement of X-guide stage 44. Guide portions 49 aresupported by surface plate 4. In the embodiment, stator 48A of Y-linearmotor 48 is provided on flat portion 49B of guide portion 49. On theother hand, a concavity-shaped guided member 50 (50A, 50B) is providedon each of both end portions of the undersurface of X-guide stage 44 inthe longitudinal direction thereof. Guide portion 49 is joined to guidedmember 50, and upper surface (guide surface) 49A of guide portion 49 isprovided so as to face the inner surface of guided member 50. Gasbearing (air bearing) 51, which is a non-contact bearing, is provided onguide surface 49A of guide portion 49. X-guide stage 44 is supported ina non-contact manner relative to guide surface 49A. Guided member 50moves along with the movement of X-guide stage 44.

Further, between stator 48A of Y-linear motor 48 and flat portion 49B ofguide portion 49 exists gas bearing (air bearing) 52, which is anon-contact bearing, and stator 48A is supported by air bearing 52 in anon-contact manner relative to flat portion 49B of guide portion 49. Forthis reason, because of the law of conservation of momentum, stator 48Amoves in the −Y-direction (+Y-direction) in response to the movement inthe +Y-direction (−Y-direction) of X-guide stage 44 and substrate tablePT. Through the movement of stator 48A, the reaction force accompanyingthe movement of X-guide stage 44 and substrate table PT is cancelled,and, at the same time, the change of the gravity center can beprevented. In other words, stator 48A has a function as a so-calledcounter mass.

Liquid supply mechanism 10 is for supplying liquid LQ to a space on theimage plane side of projection optical system PL. Liquid supplymechanism 10 comprises liquid supply portion 11 capable of deliveringliquid LQ and supply pipe 13 of which one end portion is connected toliquid supply portion 11. The other end portion of supply pipe 13 isconnected to nozzle member 70. Liquid supply portion 11 comprises a tankthat stores liquid LQ, a pressurized pump, etc. It is to be noted thatexposure apparatus EX need not be provided with all of the tank, thepressurized pump, etc., and at least a part of them may be substitutedby the facilities of, e.g., a factory in which exposure apparatus EX isinstalled.

In the midstream of supply pipe 13 is provided valve 15 that opens andcloses the flow path of supply pipe 13. The open/close operations ofvalve 15 are controlled by controller CONT. It should be noted thatvalve 15 of the embodiment is a so-called normally closed one thatmechanically closes the flow path of supply pipe 13 when the drivingsource (power supply) for exposure apparatus EX stops due to, e.g., apower outage.

Liquid recovery mechanism 20 is for recovering liquid LQ from the spaceon the image plane side of projection optical system PL. Liquid recoverymechanism 20 comprises liquid recovery portion 21 capable of recoveringliquid LQ and recovery pipe 23 of which one end is connected to liquidrecovery portion 21. The other end of recovery pipe 23 is connected tonozzle member 70. Liquid recovery portion 21 comprises a vacuum system(suction device), e.g., a vacuum pump, a gas-liquid separator thatseparates the recovered liquid LQ from gas, a tank that stores therecovered liquid LQ, etc. It should be noted that exposure apparatus EXneed not be provided with all of the vacuum system, the gas-liquidseparator, the tank, etc., and at least a part of them may besubstituted by the facilities of, e.g., a factory in which exposureapparatus EX is installed.

Nozzle member 70 is provided in the vicinity of optical element 2, whichcomes into contact with liquid LQ, among a plurality of optical elementsconstituting projection optical system PL. Nozzle member 70 is aring-shaped member that is provided so as to surround, over or abovesubstrate P (substrate table PT), the side surface of optical element 2.A clearance is provided between nozzle member 70 and optical element 2,and nozzle member 70 is supported by a certain supporting mechanism soas to be vibrationally isolated from optical element 2. Undersurface 70Aof nozzle member 70 is arranged above substrate P (substrate table PT)and faces the surface of substrate P (top face 43 of substrate tablePT). Further, each of undersurface 70A of nozzle member 70 andundersurface 2A of optical element 2 is a substantially flat surface,and undersurface 70A of nozzle member 70 and undersurface 2A of opticalelement 2 are substantially flush with each other. By this, liquidimmersion region AR2 can be formed satisfactorily within a desiredregion.

Supply port 12 for supplying liquid LQ onto substrate P is provided inundersurface 70A of nozzle member 70. A plurality of supply ports 12 areprovided in undersurface 70A of nozzle member 70. Further, an inner flowpath that connects the other end portion of supply pipe 13 to supplyports 12 is formed inside nozzle member 70 is formed.

Further, recovery port 22 for recovering liquid LQ on substrate isprovided in undersurface 70A of nozzle member 70. In the embodiment,recovery port 22 is provided, in undersurface 70A of nozzle member 70,at a position outside of supply ports 12 relative to optical axis AX ofprojection optical system PL so as to surround supply ports 12. Further,an inner flow path that connects the other end portion of recovery pipe23 to recovery port 22 is formed inside nozzle member 70.

The operations of liquid supply portion 11 and liquid recovery portion21 are controlled by controller CONT. In forming liquid immersion regionAR2 of liquid LQ onto substrate P, controller CONT delivers liquid LQfrom liquid supply portion 11 and supplies liquid LQ onto substrate Pfrom supply ports 12 provided above substrate P via supply pipe 13 andthe inner flow path of nozzle member 70. Further, liquid LQ on substrateP is recovered by recovery port 22 and is recovered by and into liquidrecovery portion 21 via the inner flow path of nozzle member 70 andrecovery pipe 23. It is to be noted that the configuration of liquidimmersion mechanism 1 is not limited to the above-described one, andsuch a configuration as described in, e.g., European Patent ApplicationPublication No. 1420298, International Publication WO 2004/055803,International Publication WO 2004/057589, or International PublicationWO 2004/057590 may be used.

Next, referring to FIGS. 2 and 3, detecting device 60 will be described.FIG. 2 is a perspective view showing substrate stage PST; FIG. 3 is aplan view of substrate stage PST.

Detecting device 60 is for detecting whether there is liquid LQ on uppersurface 41A of base member 41, which guides the movement of substratetable PT. Detecting device 60 comprises light projecting portion 61 thatemits detecting light La and light receiving portion 62 that is disposedin a predetermined position relative to detecting light La. In theembodiment, light projecting portion 61 is attached to, among the twofirst guided member 50A and guided member 50B that face each other,first guided member 50A that is disposed on the −X side relative to basemember 41, and light receiving portion 62 is attached to guided member50B that is disposed on the +X side. Light projecting portion 61 andlight receiving portion 62, which are respectively attached to firstguided member 50A and guided member 50B, are provided such that theyface each other, with base member 41 being positioned therebetween.

As described above, guided members 50 are attached to X-guide stage 44,which constitutes a portion of substrate stage driving mechanism PSTDfor driving substrate table PT. The detecting device 60 (lightprojecting portion 61 and light receiving portion 62) in the embodimentis provided on substrate stage driving mechanism PSTD for movingsubstrate table PT. Guided members 50 are movable members that beingdriven by Y-linear motors 48, and move along with X-guide stage 44relative to base member 41. Thus, it is configured such that detectingdevice 60 (light projecting portion 61 and light receiving portion 62)is attached to the movable members (guided members 50), which aremovable relative to base member 41.

As shown in FIG. 3, a plurality of (in the embodiment, two) lightprojecting portions 61 are disposed on first guided member 50A side byside along the Y-axis-direction, and a plurality of (two) lightreceiving portions 62 are disposed on guided member 50B side by sidealong the Y-axis-direction so as to correspond to light projectingportions 61. Further, it is configured such that first guided member50A, which supports light projecting portions 61, and guided member 50B,which supports light receiving portions 62, move synchronously bydriving Y-linear motors 48.

FIG. 4 is a side view schematically showing the positional relationshipbetween detecting device 60 and base member 41. As shown in FIG. 4,detecting light La emitted from light projecting portion 61 of detectingdevice 60 proceeds in a direction substantially parallel to uppersurface 41A of base member 41. And then, based on the detection resultsfrom light receiving portion 62, detecting device 60 detects whetherthere is liquid LQ on upper surface 41A of base member 41.

Light projecting portion 61 and light receiving portion 62 face eachother, and it is configured such that detecting light La emitted fromlight projecting portion 61 reaches light receiving portion 62, anddetecting light La is received by light receiving portion 62 at apredetermined level of light amount (light intensity). In thisconfiguration, if, as shown in FIG. 4, when a liquid drop (water drop)of liquid LQ is present on upper surface 41A of base member 41,detecting light La illuminates liquid LQ, then detecting light La isrefracted, scattered, or absorbed by liquid LQ. Accordingly, when thereis liquid LQ on the optical path of detecting light La, the light amount(light intensity) received by light receiving portion 62 decreases, ordetecting light La does not reach light receiving portion 62. Thus,based on the light receiving results of (the amount of light receivedby) light receiving portion 62, detecting device 60 can detect whetherthere is liquid LQ on the optical path of detecting light La. And thus,by detecting whether there is liquid LQ on the optical path of detectinglight La, detecting device 60 can detect whether there is liquid LQ onupper surface 41A of base member 41.

Since, in the embodiment, it is configured such that detecting device 60detects liquid LQ optically (in a non-contact manner), there is no needto dispose wirings or various kinds of devices in the vicinity of, e.g.,base member 41 or substrate stage driving mechanism PSTD. Thus, theamount of influence on the movements of substrate table PT and substratestage driving mechanism PSTD can be reduced.

While as detecting light La, a visible light or the like can be used, itis preferable that an infrared light having a predetermined wavelength(predetermined wavelength-band) is used. Specifically, it is preferablethat an infrared light having a wavelength of approximately 1200 nm,approximately 1450 nm, approximately 1940 nm, or approximately 2950 nmis used. Water (liquid) LQ has a property of absorbing a light havingany one of the above-mentioned wavelengths (infrared light). Thus, whendetecting light La having such a wavelength (infrared light) illuminatesliquid LQ, the light energy of detecting light La is absorbed by water(liquid) LQ, the light amount received by light receiving portion 62significantly decreases. Accordingly, the difference between the amountof light received by light receiving portion 62 when detecting light Lailluminates liquid LQ and the amount of light received by lightreceiving portion 62 when detecting light La does not illuminate liquidLQ becomes larger. Thus detecting device 60 can detect more highlysensitively whether there is liquid LQ. It is to be noted that in thecase where as detecting light La, an infrared light having theabove-mentioned wavelength is used, it may be configured such that atwo-wavelength laser light in which, for example, an infrared lighthaving a wavelength of approximately 1940 nm (2 μm-band laser light) andan infrared light having a wavelength of approximately 2950 nm (3μm-band laser light) are combined illuminates liquid LQ. Alternatively,it may also be configured such that a detecting light in which aplurality of (three or more) laser lights having different wavelengths(wavelength-bands) are combined illuminates liquid LQ.

Meanwhile, in the above-described embodiment, it is configured such thatdetecting light La proceeds in the direction substantially parallel toupper surface 41A of base member 41 and that by detecting whether thereis liquid La on the optical path of detecting light La, it is detectedwhether there is liquid LQ on base member 41. Therefore, when there isliquid LQ on base member 41, liquid LQ must be assuredly illuminated bydetecting light La. For this purpose, detecting device 60 is configuredsuch that in order to assuredly illuminate by detecting light La liquidLQ existing on base member 41, detecting light La passes inside a regionlocated within a predetermined distance from the surface of base member41 and separated from the surface. Specifically, detecting light La isset to pass through a region located within a distance of 5.5 mm fromtipper surface 41A of base member 41 and separated from the uppersurface. This will be described referring to FIG. 5.

In FIG. 5, liquid LQ in a state of liquid drop (water drop) is arrangedon upper surface 41A of base member 41. In this case, the followingformula holds:cos θ=1−(ρ×g×h ²)/(2×T),  (1A)

where θ is the contact angle of liquid LQ relative to the objectsurface, p is the density of the liquid, h is the height of the liquid(liquid drop), T is the surface tension coefficient, and g is thegravitational constant.

Since, in the embodiment, liquid LQ is water, ρ=998[kg/m³] andT=73×10⁻³[N/m] hold. By transforming the above formula (1A), thefollowing formula results:h=[(2×T)·(1−cos θ)/ρ×g] ^(1/2).  (2A)

When assuming θ=180° (cos θ=−1), h=5.46×10⁻³ [m], i.e., approximately5.5 mm results. Actually, since the contact angle θ is smaller than180°, the value of the height h also becomes smaller than 5.5 mm. Thus,by setting the distance D between upper surface 41A of base member 41and detecting light La proceeding in the direction substantiallyparallel to upper surface 41A less than 5.5 mm, detecting light La canassuredly illuminate liquid LQ existing on upper surface 41A of basemember 41.

Next, the method for exposing substrate P by using the above-describedexposure apparatus EX will be described. In order to expose substrate Ploaded on substrate table PT, controller CONT drives liquid immersionmechanism 1 to form liquid LQ's liquid immersion region AR2 on substrateP. Further, controller CONT illuminates mask M with exposure light EL byusing illumination optical system IL and projects the pattern image ofmask M onto substrate P via projection optical system PL and liquid LQ.As described above, exposure apparatus EX of the embodiment scan-exposesthe pattern formed on mask M onto substrate P while synchronously movingmask M and substrate P. As shown in FIG. 2 and FIG. 3, a plurality ofshot areas SH are set on substrate P in a matrix manner. Aftercompletion of exposure of one shot area SH, the next shot area SH ismoved, through the stepping movement of substrate P, to thescan-start-position and then exposed. Thereafter, with substrate P beingmoved in the step-and-scan manner, the scanning-exposure processes foreach of the remaining shot areas are successively performed. In order tomove substrate table PT supporting substrate P, controller CONT drivesX-linear motor 47 and Y-linear motors 48, which constitute substratestage driving mechanism PSTD. Further, being associated with the driveof Y-linear motors 48, guided member 50 (50A, 50B) supporting detectingdevice 60 also moves relative to base member 41. Here, detecting lightLa is always emitted from light projecting portion 61 of detectingdevice 60 before, during, and after exposure of substrate P.

As shown in the schematic of FIG. 6, there is a possibility that liquidLQ flows out from on substrate table PT (substrate P), and the liquid LQhaving flowed out stays on upper surface 41A of base member 41. Sincecontroller CONT is always emitting detecting light La from lightprojecting portion 61 of detecting device 60, controller CONT can detectwhether there is liquid LQ on upper surface 41A of base member 41. Here,two light projecting portions 61 are disposed side by side along theY-axis-direction, and two light receiving portions 62 are disposed sideby side along the Y-axis-direction; as shown in FIG. 6 and FIG. 3, it isconfigured such that the detecting lights La emitted from lightprojecting portions 61 pass near edge portions PTE of substrate tablePT. Liquid LQ flowing out from substrate table PT flows out from edgeportions PTE of substrate table PT onto base member 41. Thus, by makingthe detecting lights La proceed near edge portions PTE of substratetable PT, the liquid LQ flowing out from on substrate table PT can bedetected promptly and satisfactorily. In the step-and-scan movement whenexposing substrate P, the movement stroke may be small. In such case,when it is configured such that detecting light La proceeds through aportion distant from edge portion PTE of substrate table PT, therearises a possibility that it takes a long time from the time point atwhich liquid LQ flowed out onto base member 41, to the time point atwhich liquid LQ is detected by the detecting light La, and thus thedamage may spread. However, by setting the optical path of detectinglight La to be located to align with the position to which liquid LQ isapt to flow out, liquid LQ flowing out can be detected promptly andsatisfactorily.

In addition, during the exposure processes, guided member 50, whichsupports detecting device 60 (light projecting portion 61 and lightreceiving portion 62), is relatively moving relative to base member 41.First guided member 50A, which supports floodlighting portion 61, andguided member 50B, which supports light receiving portion 62, aresynchronously moved. While synchronously moving first guided member 50A,which supports floodlighting portion 61, and guided member 50B, whichsupports light receiving portion 62, controller CONT emits detectinglight La from light projecting portion 61 supported by first guidedmember 50A and detects whether there is liquid LQ on upper surface 41Aof base member 41. Since, in this way, while relatively moving detectinglight La and base member 41 by moving detecting device 60 relative tobase member 41, controller CONT detects whether there is liquid LQ onupper surface 41A of base member 41, controller CONT can, by usingdetecting device 60, detect whether there is liquid LQ with respect to arelatively large region in upper surface 41A of base member 41.

Further, by emitting detecting light La while relatively movingdetecting light La and base member 41 in a state that there is liquid LQon upper surface 41A of base member 41, liquid LQ's position on basemember 41 can be determined. More specifically, since guided member 50and substrate table PT move substantially together with respect to theY-axis-direction, the position of guided member 50, to which detectingdevice 60 is provided, can be measured by measuring the position ofsubstrate table PT by using laser interferometer 46. Thus, by emittingdetecting light La, while moving guided member 50 with the position ofguided member 50 (i.e., the position of detecting device 60) beingmonitored, controller CONT can, based on position measurement resultsfrom laser interferometer 46 and on the amount of light received bylight receiving portion 62 of detecting device 60, determine theposition of liquid LQ in the coordinate system defined by laserinterferometer 46.

Further, when detecting device 60 detects liquid LQ, controller CONTjudges based on the detection results from detecting device 60 that aproblem occurred, e.g., a problem that liquid LQ has flowed out from onsubstrate table PT. When controller CONT has judged that a problem hadoccurred, controller CONT, for example, decreases the per-unit-timeliquid supply amount by liquid supply mechanism 10 or stops supplyingliquid LQ by liquid supply mechanism 10. When stopping supplying liquidLQ by liquid supply mechanism 10, the drive of liquid supply portion 11may be stopped, or the flow path of supply pipe 13 may be closed byusing valve 15. Alternatively, based on the detection results fromdetecting device 60, controller CONT increases the per-unit-time liquidrecovery amount by liquid recovery mechanism 20. Alternatively, based onthe detection results from detecting device 60, controller CONT stopsthe exposure operation on substrate P and/or the movement of substratestage PST. In this way, by detecting, by using detecting device 60,whether there is liquid LQ on base member 41 and then by, based on thedetection results, controlling the exposure operation, liquidsupply/recovery operations, etc., it can be prevented that liquid LQflows out onto, e.g., floor face FD, and the damage spreads.

Further, when there is liquid LQ on base member 41, liquid LQ may flowinto air suction ports 42A of air bearings 42; thus, when liquid LQ isdetected, controller CONT may stop the sucking operation through airsuction ports 42A. Further, by arranging the optical path of detectinglight La to be located near air bearings 42, liquid LQ can be detectedby using detecting light La before liquid LQ on base member 41 flowsinto air suction ports 42A. Therefore, by taking an appropriate stepdepending on the detection results, it can be precluded that liquid LQhaving flowed out onto base member 41 flows into air suction ports 42A.Further, when liquid LQ penetrates between bearing surfaces 42S of airbearings 42 and upper surface 41A of base member 41, the Z-directionposition of substrate table PT may vary due to liquid LQ. However, bytaking an appropriate step depending based on the detection results fromdetecting device 60, such a disadvantage can also be prevented.

Further, when controller CONT judges that the detection results fromdetecting device 60 indicate a problem, controller CONT may raise analarm by driving alarm device K. Since, by doing so, an operator, forexample, can recognize that a problem has occurred, e.g., that liquid LQhas leaked inside exposure apparatus EX, he or she can take anappropriate step. Alarm device K may raise an alarm by using a warninglight, a warning sound, a display, or the like.

It should be noted that while, here, detecting device 60 detects liquidLQ by moving the detection region of detecting device 60 (the opticalpath of detecting light La) in cooperation with the step-and-scanmovement of substrate P, it may also be configured such that afterexposing the first shot area and before exposing the next second shotarea, it is detected whether there is liquid LQ on upper surface 41A ofbase member 41, while guided member 50 is moved in a movement conditiondifferent from the step movement. For example, it may be configured suchthat after exposing the first shot area, a detection operation isperformed with respect to a relatively large region on upper surface 41Aof base member 41 by moving guided member 50 by a distance larger thanthe step movement distance, and thereafter the second shot area isexposed. By doing so, before exposing the second shot area, it can berecognized whether there is liquid LQ on base member 41, and thus, afterascertaining that liquid LQ is absent, the second shot area can beexposed. Further, when liquid LQ is present, an appropriate step can betaken before exposing the second shot area.

It is to be noted that the detection operation by detecting device 60may be performed before the-liquid-immersion-exposure for substrate P orbefore liquid LQ is supplied onto substrate P. For example, afterascertaining, before performing the liquid-immersion-exposure, thatliquid LQ is absent on base member 41, the liquid-immersion-exposureprocess can be performed.

After completion of the liquid-immersion-exposure of substrate P,controller CONT recovers, by using liquid recovery mechanism 20 etc.,liquid LQ on substrate P or liquid LQ that stays on top face 43 ofsubstrate table PT. After recovering liquid LQ on substrate table PT,including the surface of substrate P, controller CONT can detect, byusing detecting device 60, whether there is liquid LQ on base member 41.In this case, since the exposure process on substrate P is complete,detecting device 60 can be positioned at a desired position on basemember 41 by moving, e.g., guided member 50 by a large distance.

Next, controller CONT carries out (unloads) substrate P having beenexposed from substrate stage PST. When unloading (carrying out) orloading (carrying) substrate P, controller CONT moves guided member 50by a large distance relative to base member 41 in order to movesubstrate table PT between exposure position PJ1 and load/unloadposition PJ2, as shown in the schematic of FIG. 7. Therefore, by usingdetecting device 60 supported by guided member 50, controller CONT candetect liquid LQ with respect to a relatively large region on basemember 41.

Next, substrate P, which has been exposed, on substrate table PT, whichhas been moved to load/unload position PJ2, is delivered to conveyancesystem H. It is to be noted that it may also be configured such thatcontroller CONT, after loading substrate P, which is not yet exposed, onsubstrate table PT at load/unload position PJ2 and before movingsubstrate table PT to exposure position PJ1, or after unloadingsubstrate P, which has been exposed, from substrate table PT atload/unload position PJ2 and before loading substrate P, which is notyet exposed, moves a movable member (in this case, guided member 50)supporting detecting device 60 by a large distance relative to basemember 41 and detects whether there is liquid LQ on upper surface 41A ofbase member 41.

As described above, there is provided detecting device 60 for detectingwhether there is liquid LQ on upper surface 41A of base member 41, whichguides the movement of substrate table PT. Thus, when detecting device60 detects liquid LQ, appropriate steps, e.g., a step to remove liquidLQ can be promptly taken. Therefore, the damage due to liquid LQ havingflowed out is prevented from spreading, and the exposure processes andthe measurement processes can be performed satisfactorily.

Further, with detecting device 60 capable of detecting liquid LQ beingsupported and moved by guided member 50 which is a movable member, itcan be detected whether there is liquid LQ with respect to a relativelylarge region on a member (base member 41), which is other than guidedmember 50. Thus, the damage due to liquid LQ having flowed out isprevented from spreading, and the exposure processes and the measurementprocesses can be performed satisfactorily.

It is to be noted that while, in the embodiment, it is configured suchthat each of light projecting portion 61 and light receiving portion 62is disposed, with respect to the X-axis-direction, on each of thepositions between which base member 41 exists, and that by moving guidedmember 50 in the Y-axis-direction while emitting detecting light La fromlight projecting portion 61, liquid LQ's Y-axis-direction position onbase member 41 other than guided member 50, is detected. However, bydisposing each of light projecting portion 61 and light receivingportion 62, with respect to the Y-axis-direction, also on each of thepositions between which base member 41 exists and by, with lightprojecting portion 61 and light receiving portion 62 being supported bymovable members that can relatively move relative to base member 41,emitting detecting light La from light projecting portion 61 whilesynchronously moving light projecting portion 61 and light receivingportion 62 in the X-axis-direction, the position of liquid LQ in theX-axis-direction on base member 41 can also be detected. Further, while,in the embodiment, two light projecting portions 61 and two lightreceiving portions 62 are provided, but, of course, any plural number ofeach of these portions may be provided, or only one thereof may beprovided.

It is to be noted that in the above-described embodiment, detectingdevice 60 detects whether there is liquid LQ on upper surface 41A ofbase member 41, but by changing the attaching position of detectingdevice 60 on guided member 50 to a position that is different from thatin the above-described embodiment or by attaching a new detecting device60, liquid LQ on side surface 41B of base member 41 can also bedetected, as shown in the plan view of FIG. 8.

It is to be noted that while, in the above-described embodiment,detecting device 60 is attached to guided member 50, detecting device 60may be attached to any member constituting substrate stage drivingmechanism PSTD. Alternatively, it may also be configured such that amovable member which is other than substrate stage driving mechanismPSTD and is relatively movable relative to base member 41 is provided,and detecting device 60 is attached to the movable member. For example,as shown in FIG. 9, light projecting portion 61 and light receivingportion 62 may be provided on substrate table PT's undersurface PTA,which faces upper surface 41A of base member 41. In the example shown inFIG. 9, light projecting portion 61 is attached to the −Y side edgeregion on substrate table PT's undersurface PTA, and light receivingportion 62 is attached, so as to face light projecting portion 61, tothe +Y side edge region on substrate table PT's undersurface PTA.Further, as shown in FIG. 10, light projecting portion 61 and lightreceiving portion 62 may be provided on air bearings 42 for supportingin a non-contact manner substrate table PT relative to upper surface 41Aof base member 41. In this embodiment, each of air bearings 42 isprovided on each of a plurality of position on substrate table PT'sundersurface PTA; light projecting portion 61 is provided on the sidesurface of a first air bearing among the plurality of air bearings 42,and light receiving portion 62 is provided, so as to face lightprojecting portion 61, on the side surface of a second air bearing,which is other than the above-mentioned first bearing.

Further, in the above-described embodiment, it is detected whetherliquid LQ is attaching on base member 41 having upper surface 41A, whichguides the movement of substrate table PT. However, of course, it can bedetected, by using detecting device 60 attached to a movable member,whether liquid LQ is attaching to any member that constitutes exposureapparatus EX and is other than base member 41. Further, by using suchdetecting device 60, it can be detected whether there is liquid LQ onsurface plate 4, on which base member 41 is set, or on floor face FD.

Further, detecting device 60, which detects whether there is liquid LQon base member 41, may be attached to a fixed member that does notsubstantially move relative to base member 41. For example, in theexample shown in FIG. 11, light projecting portion 61 and lightreceiving portion 62 of detecting device 60 are attached to main column3 so as to face each other, with base member 41 existing therebetween.With such a configuration also, it can be detected, by using detectingdevice 60, whether there is liquid LQ on base member 41. In addition, byoptimizing the attaching positions of light projecting portion 61 andlight receiving portion 62 on main column 3 and by using such lightprojecting portion 61 and light receiving portion 62, it can bedetermined whether there is liquid LQ on base member 41 of base member41, also whether there is liquid LQ on side surface 41B of base member41, or also whether there is liquid LQ on surface plate 4 or floor faceFD. Of course, by using light projecting portion 61 and light receivingportion 62 attached to main column 3, it can be detected whether thereis liquid LQ on any member or device that constitutes exposure apparatusEX and is other than base member 41.

It is to be noted that, in the above-described embodiment, detectingdevice 60 detects liquid LQ for forming liquid immersion region AR2, butthere is a possibility that in exposure apparatus EX, a liquid that isother than liquid LQ for forming liquid immersion region AR2, e.g., acooling liquid that cools a linear motor, flows out onto, e.g., basemember 41. Detecting device 60 can also detect such a liquid (e.g., acooling liquid).

Next, another embodiment will be described. In the followingdescription, the same or equivalent constituent elements as those in theabove-described embodiment are denoted by the same reference letters ornumerals, and their descriptions will be abridged or omitted.

By emitting a plurality of detecting lights La in a matrix manner asshown in FIG. 12, the position of liquid LQ on base member 41 can bedetermined. In FIG. 12, detecting device 60 comprises first emittingportion 61X that is disposed on the +Y side of base member 41 and emitsa plurality of detecting lights La aligned side by side with theX-axis-direction, with first light receiving portion 62X that isdisposed on the −Y side of base member 41 and is disposed in apredetermined position relative to detecting lights La emitted fromfirst emitting portion 61X, with second emitting portion 61Y that isdisposed on the −X side of base member 41 and emits a plurality ofdetecting lights La aligned side by side with the Y-axis-direction, andsecond light receiving portion 62Y that is disposed on the +X side ofbase member 41 and is disposed in a predetermined position relative todetecting lights La emitted from second emitting portion 61Y. Firstlight receiving portion 62X has a plurality of light receiving devicesthat correspond to the plurality of detecting lights La emitted fromfirst emitting portion 61X, and, similarly, second light receivingportion 62Y has a plurality of light receiving devices that correspondto the plurality of detecting lights La emitted from second emittingportion 61Y. Each of detecting lights La emitted from first emittingportion 61X and detecting lights La emitted from second emitting portion61Y proceeds in a direction substantially parallel to upper surface 41Aof base member 41, and the optical paths of these detecting lights Laare set in a matrix manner, as viewed from the top. With this setting,when, as shown in FIG. 12, there is liquid LQ on the optical path of aspecific detecting light Lax, among the plurality of detecting lights Laemitted from first emitting portion 61X, the light amount received by alight receiving device, among the plurality of light receiving devicesof first light receiving portion 62X, which corresponds to the detectinglight Lax decreases. Similarly, when there is liquid LQ on the opticalpath of a specific detecting light Lay, among the plurality of detectinglights La emitted from second emitting portion 61Y, the light amountreceived by a light receiving device, among the plurality of lightreceiving devices of second light receiving portion 62Y, whichcorresponds to the detecting light Lay decreases. Based upon thelight-reception results of each of first light receiving portion 62X andsecond light receiving portion 62Y, controller CONT can identify thatthe position of liquid LQ is located near the intersection point betweendetecting light Lax and detecting light Lay. Here, since the positionalinformation of the light receiving devices, which receive detectinglight Lax or detecting light Lay, is known beforehand from design valuesetc., controller CONT can, based upon the positional information of thelight receiving devices, which have received detecting light Lax ordetecting light Lay, determine the position of liquid LQ on base member41.

Further, as shown in FIG. 13, based upon the light receiving resultsfrom light receiving portion 62 when detecting light La is emitted fromeach of a plurality of positions on emitting portion 61, detectingdevice 60 can determine the size of liquid LQ existing on base member 41(the size of the region covered by liquid LQ).

In the example shown in FIG. 13, emitting portion 61 emits along theX-axis-direction a plurality of detecting lights La aligned side by sidewith the Y-axis-direction. Light receiving portion 62 has a plurality oflight receiving devices that correspond the plurality of detectinglights La. The positional information of these light receiving devicesis known beforehand from design values etc. When partial detectinglights La1, among the plurality of detecting lights La emitted fromlight projecting portion 61, illuminate liquid LQ, detecting lights La1do not reach light receiving devices of the light receiving portion 62corresponding to detecting lights La1, or the light amounts received bythose light receiving devices decrease. In contrast, the other detectinglights La2 reach light receiving portion 62 without via liquid LQ. Thus,based upon the light receiving results of the light receiving devices,which has received detecting lights La1, of the light receiving portion62 and upon the positional information of those light receiving devices,detecting device 60 can detect edge portions LG of liquid LQ anddetermine the size of liquid LQ (the region covered by liquid LQ).

Detecting device 65A shown in FIG. 14 has both of a function of aemitting portion for emitting detecting light La and a function of alight receiving portion for receiving the light. And, detecting device65A is provided on the side surface of substrate table PT. Detectingdevice 65A illuminates upper surface 41A of base member 41 fromthereabove with detecting light La, receives, at the same time, thelight from upper surface 41A of base member 41, and detects, based uponthe light receiving results, whether there is liquid LQ on upper surface41A of base member 41. When liquid LQ is absent on upper surface 41A ofbase member 41, the reflection light arising from detecting light Lailluminating upper surface 41A of base member 41 is received bydetecting device 65A at a predetermined level of light intensity. Incontrast, since when liquid LQ is present on upper surface 41A of basemember 41, detecting light La illuminating upper surface 41A of basemember 41 is scattered or absorbed by liquid LQ, the reflection lightthereof is received by detecting device 65A at a level of lightintensity lower than the predetermined level of light intensity. Basedupon the light receiving results with respect to the reflection light,detecting device 65A can detect whether there is liquid LQ on uppersurface 41A of base member 41. Further, in FIG. 14, on the undersurfaceof X-guide stage 44 is provided detecting device 65B that has anequivalent configuration with that of detecting device 65A. It isconfigured such that detecting light La emitted from detecting device65B proceeds near side surface 41B of base member 41. When liquid LQ isabsent on side surface 41B of base member 41, detecting light La emittedfrom detecting device 65B is reflected by surface plate 4 and thenreceived by detecting device 65B at a predetermined level of lightintensity. In contrast, since when liquid LQ is present on side surface41B of base member 41, the reflection light thereof is received bydetecting device 65B at a level of light intensity lower than thepredetermined level of light intensity, detecting device 65B can detectwhether there is liquid LQ on side surface 41B of base member 41. It isto be noted that in the embodiment of FIG. 14 also, the detectingprocess can be performed while moving substrate table PT supportingdetecting device 65A and/or X-guide stage 44 supporting detecting device65B. Further, also in this case, by using an infrared light having apredetermined wavelength as detecting light La, the accuracy ofdetecting liquid LQ can be improved.

Detecting device 65C shown in FIG. 15 has an equivalent configurationwith that of the above-described detecting device 65A and is attached toguided member 50. And, detecting lights La from detecting devices 65Cilluminate the side surfaces of air bearings 42 attached to undersurfacePTA of substrate table PT. In this regard, mirrors 66C that have areflecting surface that reflects detecting light La are provided on theside surfaces of air bearings 42. With the mirror being provided, whenliquid LQ is absent on the optical path of detecting light La, thereflection light of detecting light La, from detecting device 65C,illuminating the mirror is received by detecting device 65C at a highlevel of light intensity. For this reason, the difference of thereceived light amount between the case when liquid LQ is present on theoptical path of detecting light La and the case when liquid LQ is absentthereon becomes large. Thus liquid LQ can be detected more highlysensitively. Similarly, on guided members 50 are provided detectingdevices 65D that have an equivalent configuration with that of theabove-described detecting device 65A and illuminate side surfaces 41B ofbase member 41 with detecting lights La, and on side surfaces 41B ofbase member 41 are provided mirrors 66D that have a reflecting surface.By illuminating side surface 41B of base member 41, on which mirror 66Dis provided, with detecting light La, detecting device 65D can detecthighly sensitively whether there is liquid LQ on side surface 41B.Further, it is of course feasible that by attaching a detecting devicethat has an equivalent configuration with that of the above-describeddetecting device 65A on, e.g., guided member 50 and by illuminating theside surface of substrate table PT with a detecting light, it can bedetected whether there is liquid LQ on the side surface of substratetable PT. In this case also, by providing a reflecting surface on theside surface of substrate table PT, it can be highly sensitively whetherliquid LQ is present.

Further, not only liquid LQ attaching on the side surface of substratetable PT, but also liquid LQ that has flowed out from on substrate tablePT and runs down along the side surface of substrate table PT can bedetected by the detecting device, which can detect the liquid on theside surface of substrate table PT. Thus, when liquid LQ has flowed outfrom on substrate table PT, the liquid LQ having flowed out can bepromptly detected by using the detecting device 65, and an appropriatestep can be promptly taken.

FIG. 16 is a drawing showing a state where detecting device 65F havingan equivalent configuration with that of the above-described detectingdevice 65A is provided on undersurface PTA of substrate table PT.Detecting device 65F illuminates upper surface 41A of base member 41Awith detecting light La. In this manner, it may also be configured suchthat detecting device 65A is provided on undersurface PTA of substratetable PT. It is to be noted that a reflecting surface may be provided onupper surface 41A of base member 41.

FIG. 17 is a side view schematically showing another embodiment ofsubstrate table; FIG. 18 is a drawing of air bearing 42 viewed from thebearing surface 42S side.

In FIG. 17, on undersurface PTA of substrate table PT are provided airbearings 42 for supporting in a non-contact manner substrate table PTrelative to upper surface 41A of base member 41. Further, in airbearings 42's bearing surfaces 42S that face upper surface 41A of basemember 41 are provided blowout ports 42B that blow a gas (air) againstbase member 41's upper surface 41A and air suction ports 42A that suckthe gas between bearing surfaces 42S and guide surface 41A. Air suctionports 42A and blowout ports 42B are provided in center regions 42T ofbearing surfaces 42S of air bearings 42.

Further, as shown in FIG. 18, detecting devices 65E having an equivalentconfiguration with that of the above-described detecting device 65A areprovided in peripheral regions 42E, of bearing surfaces 42S of airbearings 42, that are other than center regions 42T, in which airsuction ports 42A and blowout ports 42B are provided. Each of detectingdevices 65E is provided in each of a plurality of predeterminedpositions in peripheral region 42E, which is located outside centerregion 42T, so as to surround center region 42T; it is configured suchthat detecting devices 65E illuminates upper surface 41A of base member41 with detecting light La and, at the same time, receives thereflection light from upper surface 41A. Thus, detecting device 65E candetect whether there is liquid LQ on upper surface 41A of base member41. Further, in bearing surface 42S of air bearing 42 are providedliquid recovery ports 26 that are capable of recovering liquid LQ onupper surface 41A of base member 41. Recovery port 26 are provided inperipheral region 42E, of bearing surface 42S, which is located outsidecenter region 42T, in which air suction ports 42A and blowout ports 42Bare provided, and each of recovery ports 26 is provided, in peripheralregion 42E, in each of a plurality of predetermined positions that areother than the positions where detecting devices 65E are located. Asshown in FIG. 17, recovery ports 26 are connected, via recovery flowpath 27, to second liquid recovery portion 28. Second liquid recoveryportion 28 has an equivalent configuration with that of liquid recoveryportion 21 described earlier. And, second liquid recovery mechanism 29that recovers liquid LQ on base member 41 is constituted by, among otherthings, second liquid recovery portion 28, recovery flow path 24, andrecovery port 26.

Also in the embodiment shown in FIGS. 17 and 18, substrate table PTsupporting substrate P and upper surface 41A of base member 41 arerelatively moved. When, during, for example, an exposure process, thereis liquid LQ on upper surface 41A of base member 41, liquid LQ on uppersurface 41A is detected by detecting device 65E. When controller CONThas judged, based upon the detection results from detecting devices 65E,that there is liquid LQ on upper surface 41A of base member 41,controller CONT can, by controlling second liquid recovery mechanism 29,recover liquid LQ on upper surface 41A via recovery port 26. In thisconfiguration, since recovery ports 26 of second liquid recoverymechanism 29 are provided in peripheral region 42E located outsidecenter region 42T having air suction ports 42A, liquid LQ on uppersurface 41A can be recovered via recovery port 26 without allowingliquid LQ to flow into air suction ports 42A, while substrate table PT(air bearings 42) and base member 41 being relatively moved. Inaddition, since, in accordance with the configuration of FIGS. 17 and18, even when there is liquid LQ on upper surface 41A of base member 41,liquid LQ on upper surface 41A of base member 41 can be recoveredwithout stopping the exposure operation on substrate P, disadvantages,e.g., a decrease of the operating rate of exposure apparatus EX can beprevented. Of course, when liquid LQ on base member 41 is detected, itmay also be configured such that the exposure operation on substrate Pis stopped, and, while relatively moving substrate table PT (airbearings 42) and base member 41, liquid LQ on upper surface 41A of basemember 41 is recovered via recovery ports 26. Further, also before orafter exposure of substrate P, the liquid recovery operation by use ofrecovery ports 26 may be performed with respect to a relatively largeregion on upper surface 41A of base member 41, while substrate table PT(air bearings 42) and base member 41 being relatively moved.

Further, with base member 41's upper surface 41A or side surface 41Bbeing made to be liquid-repellent, the liquid recovery operation can beperformed more smoothly without remaining liquid LQ. As theliquid-repellency treatment for making base member 41 to beliquid-repellent, there can be listed a treatment in which aliquid-repellent material, e.g., a fluoroplastic material, e.g.,polytetrafluoroethylene (TEFLON®), or an acrylic plastic material isapplied. Further, such a liquid-repellent material may be applied to theoverall regions on base member 41's upper surface 41A and side surface41B, or may be selectively applied to a partial region whereliquid-repellency is required.

By the way, while, in each of the above-described embodiments, exposureapparatus EX is configured to have one substrate table PT, the presentinvention can also be applied to an exposure apparatus comprising twotables. This will be described referring to FIG. 19.

Exposure apparatus EX2 shown in FIG. 19 comprises substrate table PT1that is movable in a state of holding substrate P and measurement tablePT2 that is provided in a position on a side of substrate table PT1 andis for performing various measurement processes for the purpose ofexposure of substrate P. Measurement table PT2 is a table that does nothold substrate P. On measurement table PT2 are provided measurementmarks measured by an FIA (Field Image Alignment) type substratealignment system as disclosed in, e.g., Japanese Unexamined PatentPublication Hei 4-656030 and measurement marks measured by VRA (VisualReticle Alignment) system as disclosed in, e.g., Japanese UnexaminedPatent Publication Hei 7-176468. Also, on measurement table PT2 areprovided light sensors, e.g., an illumination uniformity sensor asdisclosed in, e.g., Japanese Unexamined Patent Publication Sho 57-117238and a dose sensor (illumination sensor) as disclosed in JapaneseUnexamined Patent Publication Hei 11-16816. Thus, in exposure apparatusEX2 of this embodiment, before exposing substrate P on substrate tablePT1, various kinds of correcting processes (lens calibration processetc.) are performed by using the light sensors and measurement marks onmeasurement table PT2.

Substrate table PT1 and measurement table PT2 are, by means of a stagedriving mechanism, movable on base member 41 independently of eachother. In addition, the XY-direction positions of substrate table PT1and measurement table PT2 are measured by interferometers.

In the embodiment shown in FIG. 19, in predetermined region AR3 locateddirectly beneath projection optical system PL is formed liquid immersionregion AR2 by liquid immersion mechanism 1 described earlier, and whenperforming measurement processes, projection optical system PL andmeasurement table PT2 face each other, and with liquid LQ being filledbetween projection optical system PL and measurement table PT2, liquidimmersion region AR2 is formed. Further, when exposing substrate P onsubstrate table PT1, projection optical system PL and substrate tablePT1 face each other, and with liquid LQ being filled between projectionoptical system PL and substrate table PT1 (substrate P), liquidimmersion region AR2 is formed. In other words, it is configured suchthat liquid immersion region AR2 is formed on both of substrate tablePT1 and measurement table PT2. Further, in this embodiment, it isconfigured such that liquid LQ's liquid immersion region AR2 movesbetween substrate table PT1's surface and measurement table PT2'ssurface. When moving liquid immersion region AR2, controller CONT movessubstrate table PT1 and measurement table PT2 together within a regionincluding the above-mentioned projection area AR3 by using the substratetable driving mechanism in a state that substrate table PT1 andmeasurement table PT2 are, as shown in FIG. 19, close to or in contactwith each other and thus moves liquid immersion region AR2 between theupper surface of substrate table PT1 and the upper surface ofmeasurement table PT2. By doing so, without temporarily stopping theliquid supply operation by liquid immersion mechanism 1, liquidimmersion region AR2 can be moved between substrate table PT1's surfaceand measurement table PT2's surface in a condition that liquid LQ isprevented from flowing out through the space (gap) between substratetable PT1 and measurement table PT2.

By the way, while, in the embodiment, with liquid immersion region AR2being moved between substrate table PT1's surface and measurement tablePT2's surface in the state that substrate table PT 1 and measurementtable PT2 are close to or in contact with each other, liquid LQ isprevented from flowing out, through the gap between substrate table PT1and measurement table PT2, onto base member 41, there is an undesirablepossibility that liquid LQ slightly flows out from the gap. In order toaddress this undesirable possibility, light projecting portion 61 ofdetecting device 60 emits, as shown in FIG. 19, detecting light Latoward a region, located above base member 41, corresponding to theabove-described predetermined region AR3. It is to be noted that lightprojecting portion 61 in this case is attached to a fixed member, e.g.,main column 3. Further, light receiving portion 62 corresponding to thelight projecting portion 61 is attached in a predetermined position on,e.g., main column 3 at which light receiving portion 62 faces lightprojecting portion 61, with base member 41 existing therebetween. Bysetting, in this manner, the optical path of detecting light La to belocated depending on the region in which liquid LQ is apt to flow out,liquid LQ flowing out can be detected promptly and satisfactorily.

Further, in the embodiment of FIG. 19, on each of bearing surface 42S ofair bearing 42 provided on substrate table PT1 and bearing surface 42Sof air bearing 42 provided on measurement table PT2 are provideddetecting devices 65E having been described referring to FIG. 18. Withthis configuration, when, for example, substrate table PT1 isperforming, at the load/unload position, load/unload operations ofsubstrate P, controller CONT can detect whether there is liquid LQ onbase member 41 by using detecting devices 65E provided on air bearings42 of measurement table PT2, while relatively moving measurement tablePT2 and base member 41.

By doing so, the operating rate of exposure apparatus EX can beimproved.

Further, the present invention can also be applied to a twin-stage typeexposure apparatus comprising two stages which is disclosed in, e.g.,Japanese Unexamined Patent Publication Hei 10-163099, JapaneseUnexamined Patent Publication Hei 10-214783, and Published JapaneseTranslation 2000-505958. Also in a twin-stage type exposure apparatus,liquid immersion region AR2 can be moved between the two stages in astate that the two stages are made to be close to or in contact witheach other.

Further, as described above, the present invention can also be appliedto an exposure apparatus comprising a substrate stage and a measurementstage, as disclosed in Japanese Unexamined Patent Publication Hei11-135400.

It is to be noted that while, in each of the above-describedembodiments, liquid LQ having flowed out from on substrate table PT isdetected by using detecting light La, liquid LQ can also be detected byanother system. For example, liquid LQ can also be detected by using anoptical fiber. This will be described referring to FIG. 20 and FIG. 21.FIG. 20 is a plan view of substrate table PT as viewed from above; FIG.21 is a cross-sectional view along the line A-A of FIG. 20.

In FIG. 20, optical fiber 90 for detecting liquid LQ is a so-calledcladless optical fiber, and around its core portion through which alight is propagated is not provided any clad portion. Further, the coreportion of optical fiber 90 has a refractive index that is larger thanthat of the gas (in this embodiment, air) surrounding the optical fiberand is smaller than that of the liquid (in this embodiment, purifiedwater). For this reason, when the ambience of optical fiber 90 is filledwith air, the light is confined in and propagated by the core portion,which has a refractive index larger than that of air. That is, the lighthaving entered optical fiber 90 through incidence end portion 91 ofoptical fiber 90 exits from exit end portion 92 without the light amountbeing attenuated so much. However, when liquid (purified water) LQ hasattached to the surface of optical fiber 90, the light leaks outsidefrom the portion of the optical fiber 90 on which the liquid hasattached, because total reflection does not occur at the boundarysurface between liquid LQ and optical fiber 90. Therefore, the lighthaving entered optical fiber 90 through incidence end portion 91 ofoptical fiber 90 attenuates its light amount when it exits from exit endportion 92.

In FIG. 20, optical fiber 90 is provided along the peripheral portion ofthe tipper surface of X-guide stage 44. To incidence end portion 91 ofoptical fiber 90 is connected light projecting portion 93A capable ofmaking a light incident into optical fiber 90, and light projectingportion 93A emits a light having a predetermined light amount towardincidence end portion 91 of optical fiber 90. On the other hand, to exitend portion 92 of optical fiber 90 is connected light receiving portion93B capable of receiving the light having been propagated by opticalfiber 90 and having exited from exit end portion 92.

Based upon the light amount when the light from light projecting portion93A entered optical fiber 90 and the light amount when the light wasreceived by light receiving portion 93B, controller CONT determines thelight's attenuation ratio between optical fiber 90's exit end portion 92and incidence end portion 91 and, based upon the results, controllerCONT judges whether liquid LQ has attached to optical fiber 90, i.e.,whether liquid LQ has flowed out from on substrate table PT onto X-guidestage 44. Next, when controller CONT has judged that liquid LQ hasflowed out, controller CONT takes an appropriate step, e.g., a step tostop the liquid supply operation by liquid supply mechanism 10.

Here, X-guide stage 44 comprises stator 47A of X-linear motor 47, andstator 47A has, e.g., a coil unit and a housing portion that surroundsthe coil unit. Further, as shown in FIG. 21, the surface of X-guidestage 44 (in this instance, the surface of the housing portion of stator47A) has slanting regions 44S that are inclined such that they lowerfrom the center portion toward the peripheral portions. Optical fiber 90is located in the lowest positions of slanting regions 44S. Thus, liquidLQ having flowed out from on substrate table PT onto X-guide stage 44moves to the slanting regions 44S′ lowest positions by the action ofgravitation. Therefore, optical fiber 90 located in the slanting regions44S′ lowest positions can assuredly detect liquid LQ having flowed out.

Further, as shown in FIG. 22, instead of or in addition to theabove-described optical fiber 90, recovery pipe 93 having recovery holes92 may be provided in the slanting regions 44S′ lowest positions. Aplurality of recovery holes 92 are provided on the wall portion ofrecovery pipe 93 at predetermined intervals. The inside of recovery pipe93 is kept to have a negative pressure, and liquid LQ having flowed outonto X-guide stage 44 flows into recovery pipe 93 via recovery holes 92and is recovered.

Further, as shown in FIG. 23, the surface of X-guide stage 44 (in thisinstance, the surface of the housing portion of stator 47A) may also beconfigured to have slanting regions 44S′ that are inclined such thatthey lower from the peripheral portions toward the center portion.Optical fiber 90 is located in the lowest position of slanting regions44S′. Thus, liquid LQ having flowed out from on substrate table PT ontoX-guide stage 44 moves to the slanting regions 44S′ lowest position bythe action of gravitation. Therefore, optical fiber 90 located in theslanting regions 44S′ lowest position can assuredly detect liquid LQhaving flowed out. Further, also in the embodiment of FIG. 23, insteadof or in addition to the above-described optical fiber 90, such arecovery pipe 93 having recovery holes 92 as shown in FIG. 22 may beprovided in the slanting regions 44S′ lowest position. It is to be notedthat as the detection system of liquid LQ, a detection system using animage pickup device may also be adopted. It may be configured such thatby disposing an image pickup device on, e.g., guided member 50 and byapplying an image processing on results from the image pickup device ordisplaying on a monitor results from the image pickup device, liquid LQremaining on tipper surface 41 a of base member 41 is detected.

As described above, in the embodiments, liquid LQ is constituted bypurified water. Purified water has the advantage that it is easilyavailable in bulk in, e.g., semiconductor manufacturing factories andalso the advantage that it does not adversely affect photoresist onsubstrate P, optical elements (lenses), etc. Further, purified waterdoes not adversely affect the environment and contains scarcely anyimpurities; thus, the effect that it cleans the surface of substrate Pand the surface of the optical element provided at the end portion ofprojection optical system PL can be expected. It should be noted thatwhen the purity of the purified water supplied from, e.g., the factory,it may be configured such that the exposure apparatus itself has anultrapure water system.

The refractive index n of purified water (water) relative to exposurelight EL having a wavelength of about 193 nm is said to be approximately1.44, and when ArF excimer laser light (having 193 nm wavelength) isused as the light source of exposure light EL, the wavelength iseffectively shortened, on substrate P, as if multiplied by 1/n, i.e.,effectively becomes approximately 134 nm, and thus, a high resolutioncan be obtained. Further, since the depth of focus increases byapproximately n times, i.e., approximately by 1.44 times, compared withthat in the air, when securing of the depth of focus on par with thedepth of focus realized when the projection optical system is used inthe air suffices, the numerical aperture of the projection opticalsystem PL can be further increased; which also improves the resolution.

It is to be noted that when the liquid immersion method is used asdescribed above, the numerical aperture NA of the projection opticalsystem may become between 0.9 and 1.3. When, in this manner, thenumerical aperture NA of the projection optical system becomes large, arandom-polarized light conventionally used as the exposure light may,because of its polarization effect, adversely affect the imagingperformance; thus, a polarized light illumination method is preferablyused. In that case, it is preferable that by performing linearlypolarized light illumination in which the longitudinal direction of theline pattern of the line-and-space patterns on the mask (reticle) isaligned with the polarization direction, a lot of diffraction lightsfrom S polarization components (TE polarization components), i.e., thediffraction lights from the polarization components having thepolarization direction in line with the longitudinal direction of theline pattern are emitted from the pattern of the mask (reticle). Whenthe space between projection optical system PL and the resist applied tothe surface of substrate P is filled with the liquid, the transmittanceat the resist surface of the diffraction lights from S polarizationcomponents (TE polarization components), which contribute to theimprovement of the contrast, is higher compared with the case where thespace between projection optical system PL and the resist applied to thesurface of substrate P is filled with the gas (air), a high imagingperformance can be obtained even in the case where the numericalaperture NA of the projection optical system is over 1.0. Further, aphase shift mask, an oblique incidence illumination method (inparticular, a dipole illumination method), as disclosed in JapaneseUnexamined Patent Publication Hei 6-188169, which aligns with thelongitudinal direction of the line pattern, etc. may be appropriatelycombined with the above configuration, which works more effectively. Inparticular, a combination of a linearly polarized light illuminationmethod and a dipole illumination method works effectively when theperiodic direction of line-and-space patterns is limited to apredetermined single direction or when hole patterns are densely locatedalong a predetermined direction. For example, assuming that, when ahalf-tone type phase shift mask having a transmittance of 6% (patternhaving a half-pitch of about 45 nm) is illuminated by using acombination of a linearly polarized light illumination method and adipole illumination method, illumination σ defined by the circumscribingcircle of the two light beams forming the dipole in the pupil plane is0.95, that the radius of each of the light beams in the pupil plane is0.125σ, and that the numerical aperture NA of projection optical systemPL is 1.2, the depth of focus (DOF) can be increased by about 150 nmcompared with that when a random-polarized light is used.

Further, a combination of a linearly polarized light illumination methodand a small σ illumination method (in which the σ value defined by theratio of the illumination system's numerical aperture NAi and theprojection optical system's numerical aperture Nap becomes 0.4 or less)also effectively works.

It should be noted that, for example, when by using, for example, ArFexcimer laser light as the exposure light and using projection opticalsystem PL having a reduction magnification of about ¼, a fineline-and-space pattern (e.g., line-and-space of about between 25 and 50nm) is exposed onto substrate P, depending on the structure of mask M(e.g., the fineness of the pattern or the thickness of chrome), mask Macts as a polarization plate due to the Wave Guide effect, and theemitted amount of the diffraction lights from S polarization components(TE polarization components) becomes larger than the emitted amount ofthe diffraction lights from P polarization components (TM polarizationcomponents), which lower the contrast. In this case, the above-describedlinearly polarized light illumination is preferably employed, but evenwhen mask M is illuminated with a random-polarized light, a highresolution performance can be obtained even in the case where thenumerical aperture NA of the projection optical system PL is 0.9 to 1.3.

Further, although, for example, when a very fine line-and-space patternon mask M is exposed onto substrate P, there is the possibility that theemitted amount of the diffraction lights from P polarization components(TM polarization components) becomes larger than the emitted amount ofthe diffraction lights from S polarization components (TE polarizationcomponents) due to the Wire Grid effect, since, for example, when byusing, for example, an ArF excimer laser light as the exposure light andusing projection optical system PL having a reduction magnification ofabout ¼, a line-and-space pattern of more than 25 nm is exposed ontosubstrate P, the emitted amount of the diffraction lights from Spolarization components (TE polarization components) is larger than theemitted amount of the diffraction lights from P polarization components(TM polarization components), a high resolution performance can beobtained even in the case where the numerical aperture NA of theprojection optical system is as large as 0.9 to 1.3.

Further, not only the linearly polarized light illumination, in whichthe longitudinal direction of the line pattern on the mask (reticle) isaligned with the polarization direction, but also the combination, asdisclosed in Japanese Unexamined Patent Publication Hei 6-53120, of apolarized light illumination method in which the lights used arelinearly polarized in the tangential directions relative to a circle ofwhich center is the optical axis and an oblique incidence illuminationmethod is effective. In particular, in a case where the pattern of themask (reticle) includes not only line patterns which extend in apredetermined single direction but also line patterns which extends inmultiple different directions (a case where line-and-space patternshaving different periodic directions exist mixedly), by using, as alsodisclosed in Japanese Unexamined Patent Publication Hei 6-53120, apolarized light illumination method in which the lights used arelinearly polarized in the tangential directions relative to a circle ofwhich center is the optical axis in combination with an annularillumination method, a high resolution performance can be obtained evenin the case where the numerical aperture NA of the projection opticalsystem is large. For example, assuming that, when a half-tone type phaseshift mask having a transmittance of 6% (pattern having a half-pitch ofabout 63 nm) is illuminated by using a combination of a polarized lightillumination method in which the lights used are linearly polarized inthe tangential directions relative to a circle of which center is theoptical axis and an annular illumination method (having an annular ratioof between 3 and 4), the illumination σ is 0.95 and that the numericalaperture NA of projection optical system PL is 1.00, the depth of focus(DOF) can be increased by about 250 nm compared with that when arandom-polarized light is used, and, when assuming that a pattern havinga half-pitch of about 55 nm is illuminated and the numerical aperture NAof projection optical system PL is 1.2, the depth of focus can beincreased by about 100 nm.

Further, in addition to the above-described various kinds ofillumination methods, it is also effective to apply a progressive focusexposure method, as disclosed in, e.g., Japanese Unexamined PatentPublication Hei 4-277612 or Japanese Patent Application Publication No.2001-345245, or a multi-wavelength exposure method in which by using anexposure light of multiple wavelengths (e.g., two wavelengths), aneffect equivalent to that of the progressive focus exposure method isobtained.

In the embodiments, optical element 2 is attached to the end ofprojection optical system PL, and by this lens, the opticalcharacteristics of projection optical system PL (spherical aberration,coma aberration, etc.) can be adjusted. It should be noted that as theoptical element to be attached to the end of projection optical systemPL, an optical plate used for the adjustment of the opticalcharacteristics of projection optical system PL may be utilized.Alternatively, a plane parallel plate that can transmit exposure lightEL may be utilized. Further, while the exposure apparatus, to which theabove-described immersion liquid method is applied, is configured suchthat with the optical path space on the exit side of optical element 2of projection optical system PL being filled with a liquid (purifiedwater), substrate P is exposed, the optical path space on the incidenceside of optical element 2 of projection optical system PL may also befilled with the liquid (purified water), as disclosed in theInternational Publication WO 2004/019128.

It should be noted that if the pressure, caused by the flow of liquidLQ, of the space between the optical element located at the end ofprojection optical system PL and substrate P is high, it may beconfigured such that the optical element is rigidly fixed so as not tomove due to the pressure, instead of making the optical elementreplaceable.

It should be noted that while, in the embodiments, it is configured suchthat the space between projection optical system PL and the surface ofsubstrate P is filled with liquid LQ, it may also be configured, forexample, such that the space is filled with liquid LQ in the conditionthat a cover glass constituted by a plane parallel plate is attached tothe surface of substrate P.

It should be noted that while, in the embodiments, liquid LQ is water(purified water), liquid LQ may be a liquid other than water. Forexample, when the light source of exposure light EL is an F₂ laser, theF₂ laser light does not transmit through water, and thus, as liquid LQ,a fluorofluid that can transmit the F₂ laser light, such asperfluoropolyether (PFPE) or fluorochemical oil, may be used. In thiscase, the portions that come into contact with liquid LQ are appliedwith lyophilic treatment, by forming a thin film of a substance whichincludes, e.g., fluorine and has a molecular structure of a smallpolarity. Further, as liquid LQ, a material (e.g., cedar oil) that cantransmit exposure light EL, has a high refractive index as high aspracticable, and does not affect projection optical system PL and thephotoresist applied to the surface of substrate P can also be used. Alsoin this case, the surface treatment is applied in accordance with thepolarity of liquid LQ to be used.

It is to noted that regarding substrate P of each of the above-describedembodiments, not only a semiconductor wafer for manufacturing asemiconductor device, but also a glass substrate for a display device, aceramic wafer for a thin film magnetic head, a master mask or reticle(synthetic quartz or silicon wafer), etc. can be used.

Regarding exposure apparatus EX, in addition to a scan type exposureapparatus (scanning stepper) in which while synchronously moving mask Mand substrate P, the pattern of mask M is scan-exposed, astep-and-repeat type projection exposure apparatus (stepper) in whichthe pattern of mask M is exposed at one time in the condition that maskM and substrate P are stationary, and substrate P is successively movedstepwise can be used.

Further, regarding exposure apparatus EX, the present invention can beapplied to an exposure apparatus in which in the state that a firstpattern and substrate P are substantially stationary, the reductionimage of the first pattern is exposed at one time by using a projectionoptical system (e.g., a refraction type projection optical system thathas a reduction magnification of ⅛ and includes no reflecting element).In this case, the present invention can be applied to a stitch typeone-shot exposure apparatus in which thereafter, in the state that asecond pattern and substrate P are substantially stationary, thereduction image of the second pattern is exposed at one time ontosubstrate P by using the projection optical system in a manner that thefirst pattern image and the second pattern image partially overlap witheach other. Further, in conjunction with the stitch type exposureapparatus, the present invention can also be applied to astep-and-stitch type exposure apparatus in which at least two patternsare transferred onto substrate P in a partially overlapping manner, andsubstrate P is successively moved.

In the above-described embodiments, a light transmission type mask onwhich a predetermined light-shielding pattern (or a phase pattern/lightdecreasing pattern) is formed on a light transmissive substrate is used,but, instead of such mask, an electronic mask that forms, based upon theelectronic data of a pattern to be exposed, a transmission pattern, areflection pattern, or a light emitting pattern may also be used, asdisclosed in, e.g., U.S. Pat. No. 6,778,257.

Further, the present invention can be applied also to an exposureapparatus (lithography system) in which by forming interference fringeson wafer W, a line-and-space pattern is exposed onto substrate P, asdisclosed in the International Publication WO 2001/035168.

Further, while, in the above-described embodiments, the exposureapparatus, in which the liquid locally fills the space betweenprojection optical system PL and substrate P, is adopted, the presentinvention can also be applied to a liquid immersion exposure apparatusin which the entire surface of a substrate to be exposed is covered by aliquid. The structure and exposure operation of an exposure apparatus inwhich the entire surface of a substrate to be exposed is covered by aliquid are described in, e.g., Japanese Unexamined Patent PublicationHei 6-124873, Japanese Unexamined Patent Publication Hei 10-303114, orU.S. Pat. No. 5,825,043.

Regarding the type of exposure apparatus EX, the present invention isnot limited to an exposure apparatus, which exposes a semiconductorpattern onto substrate P, for manufacturing semiconductor devices, butcan also be applied to a variety of exposure apparatuses, e.g., anexposure apparatus for manufacturing liquid crystal display devices or adisplays, an exposure apparatus for manufacturing thin film magneticheads, an exposure apparatus for manufacturing image pickup devices(CCDs), and an exposure apparatus for manufacturing reticles or masks.

When using a linear motor (see U.S. Pat. No. 5,623,853 or U.S. Pat. No.5,528,118) in substrate stage PST or mask stage MST, either air-cushiontype linear motor using an air bearing or a magnetic levitation typelinear motor using a Lorentz force or reactance force may be used.Further, substrate stage PST may be either of a type moving along aguide or of a guideless type having no guide. Further, each of stagesPST and MST may be either of a type moving along a guide or of aguideless type having no guide.

As the driving mechanism for each of stages PST and MST, a planar motorin which by making a magnet unit in which magnets are two-dimensionallyarranged and an armature unit in which coils are two-dimensionallyarranged face each other, each of PST and MST is driven by anelectromagnetic force may be used. In this case, either one of themagnet unit and the armature unit is attached to stage PST or stage MST,and the other unit is attached to the moving surface side of stage PSTor stage MST.

Exposure apparatus EX according to the embodiments of the presentapplication is built by assembling various subsystems, including eachelement listed in the claims of the present application, in such amanner that prescribed mechanical accuracy, electrical accuracy, andoptical accuracy are maintained. In order to ensure the variousaccuracies, prior to and after the assembly, every optical system isadjusted to achieve its optical accuracy, every mechanical system isadjusted to achieve its mechanical accuracy, and every electrical systemis adjusted to achieve its electrical accuracy. The process ofassembling each subsystem into the exposure apparatus includesmechanical interfaces, electrical circuit wiring connections, andpneumatic pressure piping connections between each subsystem. Needlessto say, there is also a process where each subsystem is assembled priorto the assembling of the exposure apparatus from the various subsystems.On completion of the process of assembling the various subsystems in theexposure apparatus, overall adjustment is performed to make sure thatevery accuracy is maintained in the complete exposure apparatus.Additionally, it is desirable to manufacture the exposure apparatus in aclean room, in which the temperature, cleanliness, etc. are controlled.

As shown in FIG. 24, micro devices such as semiconductor devices aremanufactured by a series of steps, including: step 201 in which themicro device's function and performance design is performed; step 202 inwhich a mask (reticle) is manufactured based on the design step; step203 in which a substrate, the device's base material, is manufactured;substrate processing step 204 including a process in which the maskpattern is exposed onto the substrate by exposure apparatus EX accordingto the above-described embodiments; device assembly step 205 (includinga dicing process, a bonding process, and a packaging process);inspection step 206.

1. An exposure apparatus that exposes a substrate via a liquid,comprising: a movable table; a base member having an upper surface thatguides the movement of the table; and a detecting device that detectswhether there is a liquid on the upper surface of the base member.
 2. Anexposure apparatus according to claim 1, wherein the detecting devicealso detects a liquid on the side surface of the base member.
 3. Anexposure apparatus according to claim 1, wherein the detecting device iscapable of detecting a liquid on a floor face on which the base memberis provided.
 4. An exposure apparatus according to claim 1, wherein thetable is capable of holding a substrate.
 5. An exposure apparatusaccording to claim 1, wherein the detecting device detects a liquid in anon-contact manner.
 6. An exposure apparatus according to claim 1,wherein the detecting device is capable of emitting a detecting lightand performs the detection while the detecting light and the base memberbeing relatively moved.
 7. An exposure apparatus according to claim 1,wherein the detecting device is provided on a movable member that ismovable relative to the base member.
 8. An exposure apparatus accordingto claim 7, wherein the detecting device performs the detection whilethe movable member and the base member being relatively moved.
 9. Anexposure apparatus according to claim 7, further comprising: a positionmeasuring device that measures the position of the movable member onthat the detecting device is provided; and a controller that determinesthe position of the liquid based upon measurement results from theposition measuring device and detection results from the detectingdevice.
 10. An exposure apparatus according to claim 1, wherein thedetecting device is provided on a driving mechanism which moves thetable.
 11. An exposure apparatus according to claim 1, wherein thedetecting device is provided on the table.
 12. An exposure apparatusaccording to claim 1, wherein the detecting device is provided on theundersurface of the table that faces the upper surface of the basemember.
 13. An exposure apparatus according to claim 1, wherein thedetecting device is provided on a gas bearing which supports the tablein a non-contact manner relative to the upper surface of the basemember.
 14. An exposure apparatus according to claim 1, wherein thedetecting device has a light projecting portion that emits a detectinglight and a light receiving portion that is disposed in a predeterminedposition relative to said detecting light.
 15. An exposure apparatusaccording to claim 14, further comprising a first movable member thatsupports the light projecting portion and a second movable member thatsupports the light receiving portion, and wherein the detection isperformed while synchronously moving the first movable member and thesecond movable member.
 16. An exposure apparatus according to claim 14,wherein the first movable member and the second movable member areprovided so as to face each other, with the base member being locatedtherebetween.
 17. An exposure apparatus according to claim 14, whereinthe detecting light proceeds in a direction substantially parallel tothe upper surface of the base member.
 18. An exposure apparatusaccording to claim 14, wherein the detecting light proceeds near an edgeportion of the substrate table.
 19. An exposure apparatus according toclaim 1, wherein the detecting device emits a detecting light toward thebase member, receives, at the same time, a light from the base member,and detects, based upon the light receiving results, a liquid on thesurface of the base member.
 20. An exposure apparatus according to claim19, wherein a reflecting surface that reflects the detecting light isprovided on the base member.
 21. An exposure apparatus according toclaim 1, further comprising: a first table and a second table that aremovable on the base member independently of each other, and whereinwhile the first table is performing a predetermined operation in apredetermined position, a liquid is detected by using the detectingdevice provided on the second table, during the second table and thebase member are relatively moved.
 22. An exposure apparatus according toclaim 1, further comprising: a projection optical system; a liquidimmersion mechanism that supplies a liquid in a predetermined regiondirectly beneath the projection optical system to form a liquidimmersion region; a first table and a second table that are movable, ina two-dimensional plane, on the base member independently of each other;and a driving mechanism that in a state that the first table and thesecond table are close to or in contact with each other, moves the firsttable and the second table together within a region including thepredetermined region and moves the liquid immersion region between theupper surface of the first table and the upper surface of the secondtable, and wherein the detecting device illuminates a region, on thebase member, corresponding to the predetermined region with a detectinglight.
 23. An exposure apparatus according to claim 1, furthercomprising a liquid recovery mechanism that recovers a liquid on thebase member.
 24. An exposure apparatus according to claim 23, furthercomprising a controller that controls the liquid recovery mechanismbased upon detection results from the detecting device.
 25. An exposureapparatus according to claim 23, further comprising: a gas bearing thatis provided on the table and that supports the table in a non-contactmanner relative to the upper surface of the base member; and a liquidrecovery port of the liquid recovery mechanism is provided on the gasbearing.
 26. An exposure apparatus according to claim 25, wherein thegas bearing has a bearing surface that faces the upper surface; thebearing surface has a first region in which at least either one of ablowout port that blows a gas and an air suction port that sucks a gasis provided; and the liquid recovery port is provided outside the firstregion of the bearing surface.
 27. An exposure apparatus according toclaim 23, further comprising a detecting device that detects a liquid ina second region, in the bearing surface, the second region being otherthan the first region of the bearing surface.
 28. An exposure apparatusaccording to claim 23, wherein while the table and the upper surface ofthe base member being relatively moved, a liquid on the upper surface ofthe base member is recovered via the liquid recovery port.
 29. Anexposure apparatus according to claim 1, wherein at least a portion onthe base member has liquid-repellency.
 30. An exposure apparatus thatexposes a substrate via a liquid, comprising: a detecting device thatcan detect a liquid; and a movable member that is movable whilesupporting the detecting device.
 31. An exposure apparatus according toclaim 30, wherein the detecting device detects, in a non-contact way,whether there is a liquid on a predetermined member that is other thanthe movable member.
 32. An exposure apparatus according to claim 30,wherein the movable member includes a driving mechanism that moves atable that is movable while holding the substrate.
 33. An exposureapparatus according to claim 30, wherein the predetermined memberincludes a base member having a guide surface that guides the movementof the table, which is movable while holding the substrate.
 34. Anexposure apparatus according to claim 30, further comprising a firstmovable member and a second movable member, wherein the detecting devicehas a light projecting portion that emits a detecting light and a lightreceiving portion that is disposed in a predetermined position relativeto the detecting light and detects the detecting light; the firstmovable member supports the light projecting portion and the secondmovable member supports the light receiving portion; and the detectionof the liquid is performed while synchronously moving the first movablemember and the second movable member.
 35. An exposure apparatusaccording to claim 30, wherein the detecting device emits a detectinglight toward the predetermined member, receives, at the same time, alight from the predetermined member, and detects, based upon the lightreceiving results, a liquid on the predetermined member.
 36. An exposureapparatus according to claim 30, further comprising a first table and asecond table that are movable in a two dimensional plane independentlyof each other, and wherein the detecting device is provided on at leasteither one of the first table and the second table.
 37. A devicemanufacturing method, comprising: exposing a substrate via a liquid byuse of an exposure apparatus which includes: a movable table; a basemember having an upper surface that guides the movement of the table;and a detecting device that detects whether there is a liquid on theupper surface of the base member.
 38. A device manufacturing method,comprising: exposing a substrate via a liquid by use of an exposureapparatus which includes: a detecting device that can detect liquid; anda movable member that is movable while supporting the detecting device.